The subconscious isn't a pre-existing set of mental objects that's invisible to the conscious part of your mind. This would make no sense: such "mental objects" would have to be representations, and a representation is something that by definition is accessible.
On the other hand, there are things you *do*, or certain (presumably avoidable) situations you end up in, despite superficially not wanting to, and just like everything else that happens there must be a reason; but that reason is a matter of inferring what the pattern is and deducing what it enables and what in turn enables it.
Bringing such a "reason" to light is therefore not a matter of uncovering anything already there, but instead developing a vocabulary that actionably represents such patterns. This is in fact what being "conscious" of something means: to have some kind of representation of it.
In this case, what matters really is the subjectivity of the person and not any kind of objectively verifiable causality. The only "objective" criteria of veracity is whether that person is able to use this new set of affordances to adapt: what hypostasis the subject chooses to construct in order to achieve this is otherwise nobody else's business.